Quality of wildlife damage field inspections and necropsy forms
Henrik Ekstrand
Degree project in biology, Master of science (2 years), 2020 Examensarbete i biologi 45 hp till masterexamen, 2020
Biology Education Centre, Uppsala University, and Wildlife Damage Centre Supervisor: Jens Frank
External opponent: Maria Levin
Abstract
Conflict in the wake of carnivore depredation not only lead to a higher mortality in carnivore populations, but also creates conflict between humans with different interests and creates distrust in managing authorities and policy makers. Following a depredation in Sweden, an inspection and necropsy is performed. During this, a necropsy field form is filled during the inspection and necropsy. It is important that the forms are filled in correctly so correct determination of the culprit is secured. The Swedish government can only subsidize interventions if the damage is done by carnivores that are protected.Because damage done by protected carnivores is compensated by tax-payers money, wrong determinations would not be acceptable from a legal point of view and may undermine public trust in the compensation system. The study compiled the necropsy forms from depredation on sheep from brown bear, lynx, wolf, golden eagle and other source of damage depredation, filled by county administrative board surveyors.
The study evaluated and also analysed to what extent the required data has been collected, documented and if there are spatial variations. The study examined further if the number of photos attached in a necropsy form leads to more correct answers in a later evaluation by external reviewers.
Introduction
General wildlife damage, conflicts and interventions
Carnivore populations have declined worldwide, not only due to habitat loss and
fragmentation, but also due to human-induced mortality (Ripple 2011). A large part of the human-induced mortality is in the wake of conflict after livestock depredation. Mitigation through different compensation programs – by Swedish authorities – has been a tool since the 1970s to balance the cost of sharing the landscape with carnivores that attack livestock (López-Bao et al. 2017). Compensation can only be given if the damage is done by protected species that cannot be hunted under the regular hunting season (SFS 2001:724). Other than direct economical compensation for the loss of livestock, the owners can get financial support to invest in interventions to reduce the risk of depredation (NFS 2018:5). One supposedly permanent intervention is electrical fences, so-called carnivore deterring fences. Fencing is used in many parts of the world and is considered to be an effective way to prevent
depredation (Frank & Eklund 2017). But, quantitative evidence of effectiveness of
interventions, that is compared to experimental controls, and evaluations of compensation programs are lacking (van Eeden et al. 2018; Eklund et al. 2017).
Livestock damage in Sweden
The Swedish government can only subsidize interventions if the damage is done by carnivores
that are protected. In Sweden, the carnivores that are protected are brown bear (Ursus arctos),
lynx (Lynx lynx), wolf (Canis lupus), golden eagle (Aquila chrysaetos), and wolverine (Gulo
gulo). All damage on livestock done by carnivores is reported in the database Rovbase
(https://rovbase30.miljodirektoratet.no/), and compiled into a yearly wildlife damage report,
compiled by Wildlife Damage Centre (VSC) in Sweden. For livestock, other than reindeer
(Rangifer tarandus), the largest part of depredation is on domestic sheep (Ovis aries). The
wolverine has not been reported being the cause for depredation on domesticated animals
other than reindeer for the last 100 years (Levin et al. 2008). In sheer numbers, the lynx is the
carnivore that causes the most damage on sheep, followed by wolves. Considering the lynx
population is considerably larger, the per capita kill rate of wolves is higher. On average,
wolves killed 3.9 animals during attacks on domestic animals in 2013, while lynx killed 2.2 animals during attacks on domestic animals in 2013 (Ängsteg et al. 2014). In 2018, 129 sheep were killed by wolves, 195 by lynx, 5 by brown bear and 14 by golden eagle (Frank et al.
2019). The population size of wolves in Sweden, during the monitoring period 2018/19, was estimated to 300 (237-390) wolves (Naturvårdsverket 2019a). For the same period, the population size of lynx was estimated to 1 200 (1 001-1 377) animals (Naturvårdsverket 2019b). The population size of golden eagle was in the year 2018 estimated to 466 territories, of which had 220 nesting couples, where 166 couples had a successful nesting
(Naturvårdsverket 2019c). The population size for brown bears is between 2 771-2 980 individuals in Sweden. These numbers are from the population estimate for brown bears in 2017 (Naturvårdsverket 2019d).
The hunting techniques of the carnivores differs. Wolves, who are hunters with a large amount of stamina, can chase the animal for kilometres before killing or giving up (Ängsteg et al. 2014). The common characteristics for a wolf-killed sheep is bites high on the back thighs and over the nose of the sheep, where the killing bite is in the throat and neck region.
Bites on the side, chest, high on the front legs, udder and tail occur. It has not been recorded that they bite low on the front legs. The bites are very power, which results in major bleeding and crushing of bones (Levin et al. 2008). Lynx, who are ambush predators, often do not chase their prey for more than 100 meters (Ängsteg et al. 2014). They kill their prey with one or a few high precision bite or bites to the throat. Small puncture wounds can be seen from the lynx’s claws on the shoulder, back or side of the prey. It is rare to see other damages on the carcass from a lynx kill (Levin et al. 2008). The brown bear is an opportunistic omnivore that change their diet to optimize maximum energy intake in response to spatial and temporal variations (Stenset et al. 2016). Bears kill their prey with any bites to the neck, back and head, but the bite to the neck is often the killing bite. It is not common to see bites on the legs from a bear kill (Levin et al. 2008). Neither wolves, lynx or bears seems to actively search for settlements with domestic animals, but rather take an opportunity when it presents itself (Ängsteg et al. 2014). The golden eagle hunts almost exclusively in open terrain and most attacks on domestic sheep occurs during spring. The attacks are most often on young lambs.
This makes it hard to discover the attacks because the owner might not have noticed that a sheep gave birth, and a small lamb is quickly disposed of by predators. The golden eagle kills their prey by pressing their talons into vital organs. Puncture wounds can usually be seen on the head, neck, back or sides of the prey (Levin et al. 2008).
What is done when damage happen and who are involved
Inspections and autopsies in connection with predation on livestock or dogs is done by a surveyor, who is acting or working for the county administrative boards (CAB’s) in Sweden.
There are 21 CAB’s in Sweden, and their responsibilities include implementing national
objectives, co-ordinating the different interests of the county, promoting the development of
the county, establishing regional objectives and safeguarding the rule of law in every instance
(Government Offices of Sweden 2020). The surveyor is specialised in damages, tracks and
signs made by large carnivores. In order to be compensated, the owner of the livestock has to
report suspected damage done by large carnivores to their respective CAB. If the necropsy by
the surveyor determines that the damage is done by a large carnivore, the livestock or dog
owner is compensated by the CAB. The surveyor can also come to the conclusion that some other cause of damage lies behind the dead sheep, not a large carnivore. No compensation is granted if this is the case.
During the inspection, the surveyor fills in a necropsy form on site – where information about the injuries, domestic animal and owner is gathered – which is later compiled in a report and approved before entered at a later point into the database Rovbase. The approval is preferably done by another CAB official that is knowledgeable in carnivore attacks. The inspection and necropsy involve more than just determining the cause of death. The surveyor should also listen to the animal owner, handle difficult situations, leave information about carcass handling and disposal, offer help with what forms that are appropriate to fill out and give advice in which preventive measures that could be appropriate, following an attack.
Experience is needed as a surveyor, because the inflicted injuries can vary a lot, not only depending on which carnivore or cause of damage that is involved, but also depending on the carnivore individual and situation.
The methodology during an inspection involves 15 steps which end up in a report (Levin et al.
2008). The effort put in to writing the report varies (Jens Frank, personal communication, October 21, 2019), which could give rise to questions if the procedure has been performed correctly and therefore if the assessment of carnivore damage is correct. If the inspections are preformed correctly, then the forms should be filled in completely and photos showing the key signs, which is described above, that the assessment is based on should be attached. Also, it is important that the forms are filled in correctly if one would like to test if the inspection led to the correct determination at a later time. This because (1) later determinations should have the same result as the first determination, and (2) because damage done by protected carnivores is compensated by tax-payers money. Wrong determinations would not be acceptable from a legal point of view and may undermine public trust in the compensation system.
Aim of this study
This study will compile the necropsy forms filled by the CAB surveyors and analyse to what extent the required data has been collected and documented, and if there are spatial variations.
The study will also examine if the number of photos attached in a necropsy form leads to more correct answer in a later evaluation by external reviewers.
Methods
Study area and study design
The study was conducted in Sweden (64°N and 17°E; area 450,295 km2). Out of the total area of Sweden, 69% consists of forest land, 8 % of agricultural land, 8 % of heath land and
meadows, 7% open mires, 5% bare rock and other land and 3% built-up land. The landscape
in Sweden varies depending where in the country one is located. More forest lands and
mountainous areas are located in the north, while more agricultural and built-up land is
located in the south (Statistics Sweden 2019).
The form entries that was analysed had been entered between 2008-2018. Concerned cases were from where an animal owner reported a suspected attack on sheep by large carnivore (brown bear, lynx, wolf or golden eagle). The inspection and necropsy can also lead to that the culprit is not a large carnivore. Information was gathered where the suspected cause of damage was done by something other than a large carnivore, this because to see if there is a difference between these forms and the forms that lead to a carnivore. The necropsy form entries from carnivore attacks were gathered at random from the database Rovbase.
The study focused on sheep, because that is the domestic animal most often involved in depredation in Sweden (Frank et al. 2019). Information about which county the attack and inspection took place in was gathered. Five necropsy forms per carnivore species and year was analysed. That is a total of 20 inspections per year and 220 necropsy forms. All forms – with a total of 62 forms between the years 2008-2018 – for when the cause of damage is suspected to be something other than a large carnivore was gathered.
The form has the option to fill in information about the owner of the attacked sheep. For this study, it was noted if, or if not, the surveyor had filled in:
• Production site number
• Name of the owner
• Address of the owner
• Phone number of the owner
• Email of the owner
• If the owner was present at the necropsy
• If the owner got informed about the determination of the cause of damage
• Date if/or when the owner was informed about the determination of the cause of damage.
The used data was from the years 2016-2018. Due to a change in which database the surveyors were supposed to import the information to, years before 2016 lack, e.g., information about production site.
The name of the surveyor and the name of the one who approved the inspection was noted.
The surveyor has the option to take and register DNA-samples, e.g. from faecal matter of the carnivore, if the opportunity present itself. For this study, it was noted how many – if any – DNA-samples that was gathered. The number of attached photos that supports the surveyor’s determination of the source behind the damage was gathered.
The surveyor can attach the whole field form that was filled on site into the entry to Rovbase.
It was noted if, or if not, this on-site field form was attached.
An attached photo should contain a size reference and something that the surveyor can write
date, location and initials – the CAB usually have a special plate where one can write this
information. It was noted if, or if not, there was a size reference in the inspections that had
photos attached. A qualified size reference should have a unit of measurement on it. For the
plate where the surveyor can write date, location and initials, it was noted if there was no plate
visible in the photos, if there was at least one photo with the plate visible, if the plate was
visible in more than half of the attached photos and if the plate was visible in all of the photos.
An inspection can be deemed as documented, assessed or unsure. A documented inspection shall contain attached photos with a plate, containing visible, correct information. To which extent photos was attached and a plate was visible in the photos was noted for documented and assessed inspections.
Second opinion evaluation
To evaluate the quality of the attached photo documentations, 10 inspections with photos attached was randomly selected. The inspections varied in number of photos, from one photo to 19 photos. These photos were sent to 30 CAB field personnel – who are experienced in wildlife damage assessment – by email in a document. The personnel got to answer if they judged that the damage in the photos was made by a large carnivore, or not. If they answered that the damage was made by a large carnivore, they got to answer which of the large
carnivores in this study – brown bear, lynx, wolf or golden eagle – they thought was the culprit. In both cases they also had the option to answer ‘don’t know’.
Statistical analyses
The statistical analysis was performed using R software (Version 1.1.456). The data for
‘Number of photos’ was checked for normality with a Shapiro–Wilk test. A simple linear regression model was calculated:
y = β
0+ β
1x
1to see if more photos lead to a higher frequency of correct answers in a second evaluation. y is the binary response variable, x is the independent variable that explains y, β
0is the intercept (mean of y) and β
nx
1nis the slope of x.
Results
A total of 273 necropsy forms was gathered from Rovbase. Data from all of Sweden’s 21 counties was used.
In which counites is the damage done
The figures below (figure 1-5) show which of the 21 counties the necropsy forms come from,
and which carnivore that was reported to be the culprit. The figures show that the distribution
of depredation is skewed between the counties. For brown bear, a total of 52 necropsy forms
from 9 counties was gathered and analysed. Some years did not have a total of five attacks in
a year, that is the reason for not 55 forms were gathered. Forms related to bear attacks are
more common in the counties of Dalarna, Jämtland and Gävleborg (figure 1).
Figure 1. The number of inspections for depredation on sheep, that is suspected done by brown bear and in which county the inspection took place.
For lynx, a total of 55 necropsy forms from 16 counties was gathered and analysed., The county of Västra Götaland is the county where forms from lynx related attacks most frequently come from (figure 2).
Figure 2. The number of inspections for depredation on sheep, that is suspected done by lynx and in which county the inspection took place.
For wolf, a total of 55 necropsy forms from 17 counties was gathered and analysed. Forms
related to wolf attacks are more common in the counties of Västra Götaland, Värmland,
Dalarna and Örebro (figure 3).
Figure 3. The number of inspections for depredation on sheep, that is suspected done by wolf and in which county the inspection took place.
For golden eagle, a total of 49 necropsy forms from 8 counties was gathered and analysed.
Some years did not have a total of five attacks in a year, that is the reason for not 55 forms were gathered. The county of Gotland is the county where forms from golden eagle related attacks most frequently come from (figure 4).
Figure 4. The number of inspections for depredation on sheep, that is suspected done by golden eagle and in which county the inspection took place.
For when the cause of damage is suspected done by something other than a large carnivore, a
total of 62 necropsy forms from 16 counties was gathered and analysed. Forms related to
attacks that is suspected done by something other than a large carnivore are more common in
the counties of Blekinge, Västra Götaland and Östergötland (figure 5)
Figure 5. The number of inspections for depredation on sheep, that is suspected done by something other than a large carnivore and in which county the inspection took place.
To which extent is the owner information reported
For the years 2016-2018, a total of 78 necropsy forms was gathered with sheep owner information. Table 1 shows to what extent the information was reported for the different causes of damage in percent.
Table 1. The percentage of inspections where the production site number, name, address, telephone number, email, owner present, owner informed and date when informed was reported for each cause of damage for the years 2016-2018. N is the number of inspections for that specific cause of damage.
Brown bear (n=12)
Lynx (n=15)
Wolf (n=15)
Golden eagle (n=15)
Other (n=21)
Total (n=78) Owner information
Production site nr. 75 87 60 7 52 55
Name 92 100 100 93 95 96
Address 92 100 93 60 81 85
Telephone nr. 83 87 87 60 71 77
Email 25 47 40 0 43 32
Owner present 83 93 80 40 71 73
Owner informed 42 47 47 0 48 37
Date when informed 42 47 33 0 43 33
To which extent is a regional quality control done?
Out of a total of 273 inspections, 262 inspections had someone who had approved the inspection. Out of these 262 inspections, 22 inspections (8%) had been checked by another person on the CAB when entered in Rovbase. The remaining inspections had been approved by the same person that did the field inspection and necropsy.
DNA samples reported
Out of 273 inspections, nine inspections (3%) had reported that a DNA sample had been registered. Out of these nine inspections, six inspections had registered one DNA sample, two inspections had registered two DNA samples and one inspection had registered five DNA samples. That is three DNA samples registered on average.
To which extent are field forms attached?
Out of 273 inspections, 217 (79%) had a necropsy field form attached.
To what extent are photos, plate and size reference attached?
Photos was attached in 60 percent of the 273 necropsy forms. The proportion varied substantially between the different species/causes of death (table 2).
Table 2. The percentage of inspections where photos were attached for each cause of damage. N is the number of inspections for each specific cause of damage.
Brown bear (n=52)
Lynx (n=55)
Wolf (n=55)
Golden eagle (n=49)
Other (n=62)
Total (n=273)
Photos attached 63 75 76 12 38 60
Table 3 show to what degree – in percent – a visible plate was present in the inspections with
photos attached.
Table 3. The percentage of inspections, where photos was attached, that had a visible plate with date, location and initials. We investigated if the plate was visible in all of the photos, in more than half of the photos, in at least one photo or in no one of the photos. N is the number of inspections with photos attached for that specific cause of damage.
Brown bear (n=33)
Lynx (n=41)
Wolf (n=42)
Golden eagle (n=6)
Other (n=42)
Total (n=164)
All 12 24 7 0 7 12
More than half 3 17 19 0 17 14
At least one 21 20 14 17 14 17
No one 64 39 60 83 62 57
Table 4 shows the percentage of inspections where there was a size reference with a unit of measurement visible in any of the photos.
Table 4. The percentage of inspections, where photos was attached, that had a size reference in at least one of the photos. N is the number of inspections with photos attached for that specific cause of damage.
Brown bear (n=33)
Lynx (n=41)
Wolf (n=42)
Golden eagle (n=6)
Other (n=42)
Total (n=164)
Size reference 30 61 52 17 45 47
No size reference 70 39 48 83 55 53
Out of documented inspections, how many have photos attached?
Out of 273 inspections, 41 (15%) was deemed as documented. Photos were attached in 40 (98%) out of these inspections. Out of these 40 inspections, 26 (65%) had a visible plate with date, location and initials in the photos. Five inspections (13%) had at least one plate, 11 inspections (20%) had a plate in over half of the photos and 10 inspections (25%) had a plate in all of the photos.
Out of assessed inspections, how many have photos attached?
Out of 273 inspections, 224 (82%) was deemed as assessed. Photos was attached in 120
(54%) out of these inspections. Out of these 120 inspections, 42 (35%) had a visible plate
with date, location and initials in the photos. 20 inspections (17%) had at least one plate, 12
inspections (10%) had a plate in over half of the photos and 10 inspections (8%) had a plate in
all of the photos.
Second opinion evaluation
Twenty-four out of 30 CAB personnel replied back with answers. Shapiro–Wilk test for
‘Number of photos’ showed W = 0.82798, p-value = 0.03164. The data was log-transformed, which gave W = 0.9221, p-value = 0.3748. It was the log-transformed data that was used for the analyses. The Figure 6 shows the relationship between in which one is more likely to make a correct answer depending on the number of photos one gets to observe, calculated by a simple linear regression. A non-significant equation was found (F(1,8) = 0.587, p = 0.465), with a R
2of 0.0685.
Figure 6. The number of correct answers depending on the number of photos attached in the necropsy form. F(1,8) = 0.587, p = 0.465, R2 of 0.0685.
Figure 7 shows the relationship between in which one is more likely to determine if the attack
is made by a carnivore depending on the number of photos one gets to observe, calculated by
a simple linear regression. A non-significant equation was found (F(1,8) = 5.097, p = 0.0539),
with a R
2of 0.389.
Figure 7. The number of answers that did not know if the attack was made by one of the carnivores in this study, depending on the number of photos attached in the necropsy form. F(1,8) = 5.097, p = 0.0539, R2 = 0.389.
Figure 8 shows the relationship between in which one is more likely to determine which carnivore that was behind the attack depending on the number of photos one gets to observe, calculated by a simple linear regression. A non-significant equation was found (F(1,8) = 3.676, p = 0.0915), with a R
2of 0.315.
Figure 8. The number of answers that did not know which carnivore in this study that made the attack, depending on the number of photos attached in the necropsy form. F(1,8) = 3.676, p = 0.0915, with a R2 of 0.315.
Discussion
This study has compiled to what degree inspections and necropsy forms from CAB field personnel are correctly executed and to what degree the forms differ between the cause of damage.
All 21 counties were represented in the form gathering from Rovbase, but not all carnivores did depredation on sheep in all counties. This could be an effect of the different distributions of the carnivores. The brown bear is unevenly distributed in the northern part of Sweden, and has its highest density in parts of the counties of Dalarna, Gävleborg, Jämtland,
Västernorrland, Västerbotten and Norrbotten (Kindberg et al. 2011). This correlates with the results in this study, where the most forms come from the counties Dalarna, Jämtland and Gävleborg. Why Västernorrland, Västerbotten and Norrbotten is not equally high as the other three is because these counties are located further north in the country, where agricultural land and sheep owners are scarcer (SCB 2007). For lynx, Västra Götaland, which is located in the south west of Sweden, was the county that stood out from the rest, in terms of necropsy form entries. The lynx’s distribution in Sweden ranges from the far north to the south (Samelius et al. 2012). The lynx’s main food source in Sweden is small to medium size ungulates, where reindeer is the preferred diet in the north and roe deer (Capreolus capreolus) in the south (Yom-Tov et al. 2010). One could assume that the lynx would select sheep if their main food source – roe deer in southern Sweden – was scarce. But, in the study of Odden et al. (2008), they showed that lynx did not show a selection for sheep grazing areas. They showed that the probability of a lynx using an area increased if that area was suitable for roe deer. This shows that the lynx is more likely to be located in areas with a high density of their preferred food source, not which food source that is more available. Therefore, lynx depredation on sheep is more of a question on chance encounters rather than selection. Sheep grazing areas is
associated with human activity, which are a higher mortality risk for large carnivores and are normally avoided. But, with a high chance to prey on their preferred food source, a trade-off can occur (Bunnefeld et al. 2006). The county of Västra Götaland houses about 72 865 sheep, lambs and rams (SCB 2007), so the chance of a lynx encountering these domestic animals are relatively high, compared to for example the county of Västerbotten, which houses 8 537 sheep, lambs and rams. The most forms related to wolf attacks came from the counties of Västra Götaland, Värmland, Dalarna and Örebro. This corelates with the wolf distribution in Sweden, which is limited to the south-central region (latitude 54°N and 75°N; longitude 27°
and 14°E) (Karlsson et al. 2007). The wolf’s diet is varied, but wild ungulates is its main prey. In Sweden, the elk (Alces alces) is by far the most hunted and consumed prey (Müller 2006). The county of Västra Götaland is not the county which houses the most wolf
territories, but is still the county where the most depredation on sheep seems to occur. What
limit wolf distribution is not elk density – because the wolf is not an obligatory hunter on elk
– but rather the proportion of built-up areas, roads and open land, which is associated with
human activity (Karlsson et al. 2007). Wolves do not actively seek livestock pastures. They
are motivated to pass through these areas by other factors (Chavez & Gese 2006). The wolf
usually wanders when they are to establish new territory. In Scandinavia, wolves have been
observed to wander up to 1100 km (Levin et al. 2008). The high depredation frequency in
Västra Götaland is probably due to the same reason as for the lynx – due to the high number
of sheep located in the county. Gotland was the county that attacks related to golden eagle
came from. Gotland is an island and no other of the carnivores in this study is present on the
island. Though the most golden eagles can be found in the northern part of Sweden, the
county of Gotland have the highest density of golden eagle (Naturvårdsverket 2019c). the
golden eagle has a broad diet and can – depending on spatial and temporal difference – be
considered both as a generalist and a specialist (Moss 2011). The golden eagle hunts almost
exclusively in open terrain and in the north, depredation on reindeer is most common for the golden eagle (Levin et al. 2008). Why a not more evenly distributed attack rate over different counties can be seen is most likely due to the high density of both sheep and golden eagles on Gotland. The county is housing 61 068 sheep, lambs and rams (SCB 2007). Also, in other parts of Sweden, other sources of food are available. The golden eagle feeds mainly on black grouse (Lyrurus tetrix), capercaillie (Tetrao urogallus), mountain hare (Lepus timidus) and elk in the northern forests and mountains. Carrion is also an important food source in these
regions (Watson 2010), which may be lacking on Gotland. For attacks that was deemed to be done by something other than a large carnivore, Blekinge was the county with the most necropsy form entries, followed by Västra Götaland and Östergötland. Neither wolf or bear is having a home range present in this county. That this county stood out is perhaps due to that people living there is not as accustomed to carnivore attack as other people, and are more prone to involve the CAB compared to people living in more carnivore-dense counties.
People in other counties may feel surer that the sheep got killed by something other than a carnivore, if that is the case, and they feel no need to involve CAB unnecessarily.
For owner information, the name and address of the owner was reported most frequent.
Between brown bear, lynx and wolf, no clear differences were obvious. Neither was there any clear differences between when the cause of damage was suspected to be something other than a carnivore and these three carnivores. The inspections from suspected golden eagle attacks however stood out. Only 7% of these inspections had reported a production site number and none of these inspections had email, if the owner got informed about the
determination of the cause of damage and date if/or when the owner was informed about the determination of the cause of damage reported. Only three out of the 11 years was represented in this analysis, due to change of database where the report is entered. In years before 2016, only name, address and telephone number of the owner was reported.
When the report is about to be entered to Rovbase, it is checked and approved by CAB personnel, experienced in carnivore attacks. This is preferably done by another than the one who made the field inspection and necropsy. Through this study, it was found that only 8% of the 273 inspection forms had someone else that approved the inspection form.
This study showed that DNA samples from inspections are gathered to a low extent. Out of the 273 inspection entries, 3% had reported that DNA samples was gathered. In this case, there might just not be any matter to gather DNA from around. But it is possible to obtain salivary DNA samples thorough buccal swab samples from bite wounds. In the study of López-Bao et al. (2017), they did a DNA salivary analysis on 68 randomly selected sheep carcasses, that had been deemed by surveyors to be killed by wolves or lynx. Their results showed that the surveyors were able to correctly identify the culprit to 87% of the cases. A shift in focus to more DNA sampling in the future would minimise the risk of
misidentification.
Out of 273 inspections, 217 (79%) had a necropsy field form attached. Because it is not mandatory to attach the necropsy field form, it is easy to leave it out. If the field form is considered important it may be beneficial to make it mandatory to attach it.
Photos was attached in 60% of all cases. No major difference was seen between forms coming from suspected brown bear, lynx and wolf attacks. For the other two causes of damage,
photos were attached to a lower extent, with 12% for golden eagle and 38% for other. The
inspections from damage done by golden eagle did not, to a high extent, have a plate in the
visible in the six inspections with photos attached. No inspection had a plate visible in above
half of the photos and 17% of the inspections had at least one plate visible. Lynx had the highest frequency of visible plates compared to the other causes of damage. The lynx
inspections were also the only cause of damage where the proportion to have at least one plate or more was higher than to have no plate at all. Of the inspections that were deemed
documented, there was a high frequency to have photos attached (98%). However, 35% of these inspections did not have a visible plate in any of the attached photos. If the inspection and necropsy is to be deemed documented, a visible plate should be in at least one photo. This regional difference in attaching photos is most likely due to regional differences in what is accepted in carrying out the inspection and necropsy. This can and should be addressed, so equal quality is secured over the country and trust is built towards the CAB’s.
The regression analysis for if more photos in an inspection leads to more correct answers and less insecurity in decrementing the cause of damage did not show a significant relationship.
The simple linear regression (figure 6) showed a p-value of 0. 0.465. The two remaining simple linear regressions (figure 7 & 8) of the number of answers that did not know if the attack was made by one of the carnivores in this study and the number of answers that did not know which carnivore in this study that made the attack showed p-values of 0.0539 and 0.0915 respectively. But, somewhat of a trend can be seen observing the results. The
conclusion from this analysis is that it may not be the number of photos that make a difference – even though there is a higher chance that right determination becomes easier with more photos – but the quality. Some of the photos was just of the pasture where no chance of determining the cause of damage was possible.
With the return of large carnivores to parts of Europe where they earlier were absent from, have given rise to conflicts in its wake. Humans have historically competed with carnivores over resources, which had led to hunting and killing of carnivores, resulting in a major threat to their populations (Ohrens et al. 2019). The large carnivores had their lowest abundance during the 1950-1970s, and has since then made a comeback to where Europe hosts several large and stable populations. Brown bear, lynx and wolf populations can be found in human- dominated landscapes, outside protected areas (Chapron et al. 2014). The golden eagle is distributed over five biogeographic regions in Europe; the North-West Mountains, East Baltic Lowlands, West Mediterranean Mountains, Alpine Mountains and Balkan Mountains. Even though the population is reportedly stable or increasing in most of the European countries, the golden eagle occurs in low densities, and therefore are susceptible to the risk small
populations face (Watson 2010). Because the large carnivores have been a conflicting subject through history, they are in our modern and crowded world among the species that are the most difficult to apply conservation actions towards (Chapron et al. 2014). Mitigation strategies are in place in Sweden to minimize social and economic conflicts, such as the compensation programs described above. But, for these compensation programs to be effective, reliable quality-assured documentations and reports are required from the
inspections and necropsies performed on the livestock allegedly killed by carnivores (López- Bao et al. 2017). Successful management interventions build on social trust, i.e., to be willing to rely on managing authorities, policy makers and those implementing interventions. Humans process trust-related perceptions via two systems. The first is an automatic, unconscious, associative system, which is often referred to as social emotion. The second one is an intentional, conscious, rule-based system, which is often referred to as decision making, problem solving or logical thinking (Cvetkovich & Winter 2003). To build social trust towards the authorities and policy makers, accuracy when verifying livestock damages is important. Without a correct performed inspection and necropsy, that ensures that the result can be replicated, compensation programs lose social trust from the public (López-Bao et al.
2017). These programs, that give economic incentives, are important to increase tolerance for
these carnivores (Treves & Bruskotter 2014), which is crucial for effective conservation and
management for these carnivores. Without that the interventions and compensation programs
are perceived as effective; it makes little matter that the interventions and compensation
programs are functional effective (Ohrens et al. 2019). Therefore, it is important that the
inspections and necropsies are performed and reported with the same level of accuracy and
precision throughout all counties in Sweden.
References
